ATK breathe life into Liberty via unfunded NASA Space Act Agreement

The company made famous in the space flight industry for their giant Solid Rocket Boosters (SRBs) have put their hat into the ring for potentially carrying NASA astronauts to Low Earth Orbit (LEO) via their Liberty launch vehicle. Looking very much like the cancelled Ares I – Liberty will use a five segment booster with a Ariane 5 core stage as the Upper Stage.

The agreement allows for NASA collaboration on the development of the company’s Liberty Launch System as part of the CCDev-2 activities, but without NASA funding. Their goal will be to successfully impress NASA enough to be brought back into the fold by the time the CCDev-3 awards are made in 2012.

“This agreement will provide the opportunity to look at the Liberty system to understand its design solution and risks, its capabilities and how it could be used to fly our NASA crew,” said Ed Mango, NASA’s Commercial Crew Program manager. The program is based at the agency’s Kennedy Space Center in Florida.

NASA will provide feedback to ATK based on its human spaceflight experience for advancing crew transportation system capabilities and the agency’s draft human certification requirements.

“With this SAA we believe NASA will benefit from gaining insight into the various systems we are developing, and we can benefit from the feedback,” said Kent Rominger, vice president, strategy and business development for ATK Aerospace.

“In the end, we hope to offer a commercial solution to NASA, the Department of Defense, and other commercial human spaceflight programs.”

Liberty Launch Vehicle – First Stage:

With the appearance of an Ares I – given it works on the same aerodynamic design principle – Liberty is powered by a single, five segment Solid Rocket Booster (SRB) on the first stage.

The large solid motor was set to power the Ares I, prior to the cancellation of Constellation – and may find a role with the Space Launch System (SLS), with two five segment boosters currently part of the Design Reference Vehicle (DRV).

Also known as “Resonant Burning” – described as vortices that shed within the solid rocket motors during combustion due to the shearing of internal flow at propellant discontinuities – the issue relates to when the frequency of thrust oscillations is coincident with the acoustic modes of the motor cavity.

When pressure oscillations drive resonant modes in the vehicle structure, these oscillations are capable of rendering the astronauts incapacitated, or worse.

This was the major concern, that crew health was at risk during the few seconds TO occurs, late in first stage flight. However, engineering work during the Ares I development created several options to mitigate TO on Ares I’s first stage reaching the crew seated in Orion, this risk has – it was claimed – been eliminated.

Notably, the Liberty Upper Stage is also a different design when compared to the Ares I Upper Stage, further decoupling the potential TO effects, especially as TO was heavily related to the Ares I stack in the configuration with the Orion crew vehicle.

Should any concerns remain, the use of dampers and isolation – as seen with Ares I – could be used. TO is of no concern to SLS, given the configuration of the Heavy Lift Launch Vehicle (HLV).

The redesign eliminated the highest – although extremely unlikely to occur – “critical 1” failure scenario, which held the potential of a LOV/C (Loss of Vehicle/Crew) event.

The change to the fuel pump related to a small carbon seal that could be lost/compromised during operation, allowing for two metal surfaces to contact – which would become an ignition source.

As noted in the FRR and Program Requirement Control Board (PRCB) documentation (L2), this change, along with the other numerous tweaks and improvements over the years, would have been implemented on the Ares I First Stage, and thus now find themselves adding to Liberty’s safety regime.

“We believe Liberty offers the safest, most reliable means of putting our crews on orbit,” noted Mr Rominger. “We have the capability – with 44,000 lbs to Low Earth Orbit (LEO) – to launch any of the commercial crew vehicles that are out there to date.”

The latest generation of the Ariane 5 is based on an evolution of the Vulcain engine that powers the cryogenic core stage. This evolution, called Vulcain 2, provides an increased thrust through an overall mixture ratio and liquid oxygen mass flow increase.

The EPC stage is 5.4 m in diameter and 31 m long on the Ariane 5. It is powered by one Vulcain 2 engine that burns liquid hydrogen (LH2) and liquid oxygen (LO2) stored in two tanks separated with a common bulkhead. The LO2 tank is pressurized by gaseous helium and the LH2 one by a part of gaseous hydrogen coming from the regenerative circuit.

The engine is turbopump-fed and regeneratively cooled. The thrust chamber is fed by two independent turbopumps using a single gas generator. A cluster of GH2 thrusters are used for roll control.

The engine utilizes two turbo-pumps, driven by a gas generator, and sports a GHe pressurization system for the LOX tank and GH2 for LH2 tank.

Ignition of the engine is obtained by pyrotechnic igniters and occurs nine seconds before lift-off in order to check that’s it’s functioning properly, which leads to the main outstanding question on the use of this core stage on the Liberty Upper Stage, as it has yet been proven that the engine can be air-started, as would be required during its role with Liberty.

John Schumacher, vice president, Space Programs, EADS North America, noted that preliminary work has taken place on this requirement, when talking to reporters on Tuesday, but did not elaborate on when the work would be completed.

The engine has a record of 45 consecutive successful flights with the Ariane 5.

The mating of the ATK Solid Rocket First Stage with the Ariane 5 Core Stage is a great fit, for several reasons, according to Mr Rominger.

“What’s really fascinating with is how well the Upper Stage matches up with our First Stage. You would think they would have been designed to go with each other, but in fact they weren’t – yet they matched up better than if we had intentionally designed it that way.

“The other thing I’d like to emphasize is that in 2010, President Obama signed in a new space policy, which said we want to expand our international cooperation in space flight. So we’re taking what we believe is a very good relationship from the ISS with the European Space Agency and NASA and involving that legacy into the commercial world,

“So if you look at the Liberty system, NASA developed the first stage, and the upper stage was developed by ESA. Two companies are taking that and applying it commercially.”

Launch Infrastructure:

Liberty would launch from the Kennedy Space Center (KSC), Pad 39B, again utilizing the Ares I approach of utilizing what is now a clean pad, which has left Pad 39A in its shuttle configuration.

“We (ATK) asked to come into the Kennedy Space Center, because this is going to be the home of Liberty,” noted Mr Rominger, adding that Liberty could create around 300 jobs at the Florida spaceport. “Clearly the infrastructure, here at the Kennedy Space Center, is set up perfectly to process Liberty, to launch Liberty and (use) the people here.

“We would use the expertise that we have developed here over the last five decades. We are looking to take advantage of the great capability that is here today.”

It is likely the Upper Stage could be barged all the way to the VAB, utilizing the canal and turn basin previously used to ship the shuttle’s External Tank (ET) from the Michoud Assembly Facility (MAF) in New Orleans.

Such a sight wouldn’t be seen until 2015, which ATK and NASA note is Liberty’s current IOC (Initial Operating Capability) target.

Importantly, Liberty is without a crew transport to launch, as much as ATK have noted they have already had positive conversations with some of the commercial crew carriers.

Attracting a successful commercial crew partner will be key for Liberty’s forward path.

(Images: Via L2 and ATK) (As the shuttle fleet retire, NSF and L2 are providing full transition level coverage, available no where else on the internet, from Orion and SLS to ISS and COTS/CRS/CCDEV, to European and Russian vehicles.